More than 100 retired civil servants yesterday urged the government to redevelop their co-operative housing estates, which officials say can generate 19,000 medium-sized flats.

"[Chief Executive] Leung Chun-ying has been trying to increase land supply by different means such as developing the New Territories North, but there are difficulties," said Wong Pak-yan, the convenor of a petition forum on the redevelopment of co-operative housing yesterday.

"But our land is here, available for you to take. We want you to take it for everyone's sake."

Under the Civil Servants Co-operative Building Society Scheme launched in 1952, government employees were granted land at a concessionary premium - usually a third of the market value - to build flats through co-operative societies.

The scheme, which ended in the mid-80s, stipulates that the owners cannot sell their flats unless at least 75 per cent of the members agree to dissolve the society and all members agree to sell the site and pay a land premium - defined as the difference in the value of the lot before and after redevelopment.

Only 11 of the 238 estates have been redeveloped so far, official data showed, but many estates are already vacant as most retired residents are too old to live in the buildings without lift access. The remaining 227 estates have about 963,000 square metres of domestic gross floor area.

Wong, who lives with his wife in one such estate in Cheung Sha Wan, yesterday urged the government to either waive the land premium for redevelopment so that property developers would have more incentive to buy them, or to let the Urban Renewal Authority acquire these estates.

In response, development minister Paul Chan Mo-po said the government was open to the possibility of redeveloping the sites and would consider how best to deal with the issue.

To increase long-term land supply, Chan said, the government would in two months' time be putting forth a consultation on the creation of huge artificial islands west of Hong Kong Island.

Meanwhile, the chief executive yesterday defended himself on a TV programme in response to public criticism that he had failed to address the city's deep-seated housing problems in his maiden policy address.

"I daresay that in the past 15 years, no chief executive or government had had such great determination to respond to the society on the [issue of these] housing problems," said Leung.

"If anyone thinks that either my administration or I have succumbed to the property developers, they will have to offer concrete examples."

This article appeared in the South China Morning Post print edition as Take our housing estates, ex-civil servants tell C.Y.